Patent GB-1216824-A (GB)
Title: High power hydrogen thyratron
IPC: H01J17/06
Filed: 1969-03-17
Abstract: 1,216,824. Gas-filled thermionic valves. UNITED STATES ATOMIC ENERGY COMMISSION. 17 March, 1969 [19 April, 1968], No. 13954/69. Heading H1D. A hydrogen thyratron discharge tube includes an anode 12 having a continuous, smoothly rounded surface and a grid structure 11, coaxially surrounding and insulated from the anode, comprising a number of symmetric conductive shells all having smoothly rounded surfaces. As shown in Fig. 1, these shells comprise a bowl-shaped shell 15 equidistantly spaced from the centrally extending end 13 of the anode, a first set of axially spaced annular shells 14 with apertures therebetween for admitting electrons along paths 22, each shell 14 being convex towards the anode, and a second set of annular shells 24 disposed coaxially surrounding the apertures between the shells 14, with their concave side towards the anode. The shells 14 and 24 are electrically and mechanically connected by bridging struts 25 which also support the shells 24. This gridanode structure can hold off voltages of the order of 100 kv. without disruptive field emission. In a modification, Fig. 4, only one shell 47 and one shell 48 are present, and the upper end of shell shell 47 may be secured directly to the envelope, Fig. 2 (not shown). The hollow anode may be cooled by circulating water therein. 1,216,825. Lasers; cathode-ray tubes. INTERNATIONAL BUSINESS MACHINES CORP. 18 March, 1969 [15 July, 1968], No. 14007/69. Headings H1C and H1D. [Also in Division H4] In a laser as described in Specification 1,123,840 in which a charge produced by an electron beam on a selected area of an electrooptic crystal alters the polarization of an incident polarized light beam and so controls the direction of emitted radiation, the charge is erased by the provision of a set of reflective conductive strips which together form a resonator mirror, each strip being connected to ground through a respective leakage resistor. As shown in Fig. 1 two sets of reflective strips 19, 39 are provided, each being placed on a surface of a respective electro-optic crystal 17, 37 and forming capacitors with a transparent electrode 18, 38 coated on the opposite surface. Parallel reflective strips 60-69, Fig. 2, each grounded through a leakage resistor 70-79 and optionally provided with separate targets for a directioncontrolled electron beam 22, 42, may be used, the two sets of strips being spatially oriented so that one set is orthogonal to the other. In a modification, Figs. 3 and 4 (not shown), one set of strips is in the form of concentric rings while the other presents a radial pattern. Associated with each electro-optic crystal is a polarizer 4, 5 and a birefringent quartz plate 15, 35, these components together with lenses 2, 3 and the strip area of each crystal on which an electron beam charge is selectively applied causing an active medium 1 such as a mercury discharge to emit a single beam 1 in a controlled direction. The leakage resistors may be photoconductors and have their resistance lowered by energizing a lamp 131A to more rapidly remove the charge. The output is extracted by an inclined glass plate 139. In a modification, Fig. 5, a folded resonator is provided by the use of a partiallytransmitting reflector 91, a single lens 92, polarizer 93, birefringent plate 94 and electrooptic crystal 98 being required in this case. The two sets of reflective strips are formed on different zones 110, 111, Fig. 6, of the electrooptic crystal for scanning by separate electron beams 99, 100 and are orthogonally arranged.